// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_BLINK_CDM_RESULT_PROMISE_H_
#define MEDIA_BLINK_CDM_RESULT_PROMISE_H_

#include <stdint.h>

#include "base/macros.h"
#include "media/blink/cdm_result_promise_helper.h"
#include "third_party/WebKit/public/platform/WebContentDecryptionModuleResult.h"
#include "third_party/WebKit/public/platform/WebString.h"

namespace media {

// Used to convert a WebContentDecryptionModuleResult into a CdmPromiseTemplate
// so that it can be passed through Chromium. When resolve(T) is called, the
// appropriate complete...() method on WebContentDecryptionModuleResult will be
// invoked. If reject() is called instead,
// WebContentDecryptionModuleResult::completeWithError() is called.
// If constructed with a |uma_name|, CdmResultPromise will report the promise
// result (success or rejection code) to UMA.
template <typename... T>
class CdmResultPromise : public CdmPromiseTemplate<T...> {
public:
    CdmResultPromise(const blink::WebContentDecryptionModuleResult& result,
        const std::string& uma_name);
    ~CdmResultPromise() override;

    // CdmPromiseTemplate<T> implementation.
    void resolve(const T&... result) override;
    void reject(CdmPromise::Exception exception_code,
        uint32_t system_code,
        const std::string& error_message) override;

private:
    using CdmPromiseTemplate<T...>::IsPromiseSettled;
    using CdmPromiseTemplate<T...>::MarkPromiseSettled;
    using CdmPromiseTemplate<T...>::RejectPromiseOnDestruction;

    blink::WebContentDecryptionModuleResult web_cdm_result_;

    // UMA name to report result to.
    std::string uma_name_;

    DISALLOW_COPY_AND_ASSIGN(CdmResultPromise);
};

template <typename... T>
CdmResultPromise<T...>::CdmResultPromise(
    const blink::WebContentDecryptionModuleResult& result,
    const std::string& uma_name)
    : web_cdm_result_(result)
    , uma_name_(uma_name)
{
}

template <typename... T>
CdmResultPromise<T...>::~CdmResultPromise()
{
    if (!IsPromiseSettled())
        RejectPromiseOnDestruction();
}

// "inline" is needed to prevent multiple definition error.

template <>
inline void CdmResultPromise<>::resolve()
{
    MarkPromiseSettled();
    ReportCdmResultUMA(uma_name_, SUCCESS);
    web_cdm_result_.complete();
}

template <typename... T>
void CdmResultPromise<T...>::reject(CdmPromise::Exception exception_code,
    uint32_t system_code,
    const std::string& error_message)
{
    MarkPromiseSettled();
    ReportCdmResultUMA(uma_name_,
        ConvertCdmExceptionToResultForUMA(exception_code));
    web_cdm_result_.completeWithError(ConvertCdmException(exception_code),
        system_code,
        blink::WebString::fromUTF8(error_message));
}

} // namespace media

#endif // MEDIA_BLINK_CDM_RESULT_PROMISE_H_
